This discussion focuses on ensuring that a sensor output accurately represents the temperature it is intended to measure. For example, suppose it is desired the outdoor temperature. This measurement could employ s large dial thermometer, ehice might be placed on a fooball field or atennis court in the direct sunlinght, and assumed to represent “ the temperature,” perhasps as high as50c (120F) But what temperature is begin indicated by this thermometer Certainly the thermometer is not measuring the air temperature, nor is it measuring the temperature of the field or the court. The thermomenter is subject to the very sources of error we wish to describe and analyze.